>”Yet the extinction of Neanderthals, at least, took a long time – thousands of years. This was partly because early Homo sapiens lacked the advantages of later conquering civilisations”

Is it possible we “simply” outbred them? If one population breeds slowly compared to another one of them will be swallowed by the other and not necessarily primarily through violent means.

The answer is probably that we were able to kill them because we were able to outbreed them. They fit into a similar ecological niche, so they would have been competition.

In principle, yes. But the record of History argues otherwise.

... and the other eight were delicious.